The present invention relates to apparatus for controlling a braking system.
A friction braking system for a railway train is powered from an air supply. The level of brake demand has been traditionally controlled by an on car control valve (the distributor valve) which senses the air pressure in a brake control pressure pipe, the pressure in this pipe dictating the current brake demand.
Such a system has generally (but not always) been used for freight applications where no electrical supply has been available.
However the rail industry may move in the future to a system where an electrical supply is made available throughout the train. In this circumstance the brake control pressure pipe control system will be replaced with an electrical equivalent, i.e. a serial communications link or a radio link.
Nevertheless, a period of time will exist where trains will be made up of mixed cars, some being purely air controlled and some electrically controlled. In the transition period the electrically controlled units will need to be dual systems being able to use either the brake control pressure pipe or the electrical control signal system.
According to the present invention, there is provided apparatus for controlling a brake system operable using an air supply, the apparatus including electronic control means for controlling air distribution and air to electrical conversion means for generating an electrical supply for energising the electronic control means using air under pressure from said air supply.
Said air supply could be derived from sources including a train brake control pressure pipe or a train brake supply pipe, for example.
Said air to electrical conversion means may be supplied with said air under pressure directly from said air supply.
The apparatus may include a distributor valve coupled with said air supply and which is controlled by said electronic control means and distributes air to at least one brake actuator of the apparatus via a supply connection.
In this case said air to electrical conversion means may be supplied with said air under pressure from an exhaust outlet of said distributor valve and/or from said supply connection.
Said electronic control means may control air distribution either as a result of sensed pressure in a brake control pressure pipe or as a result of an electronic brake control signal. Such an electronic brake control signal may be providable via a signal line and/or a radio link control (which control may have an electrical supply provided by said air to electrical-conversion means).